Centroid Community CNC Support Forum

My Machine is a 1984 Supermax YCM 16v Knee Mill(Bridgeport Clone, with Low and High Range only) Can someone please tell me what the heck I'm doing wrong? My spindle speed encoder is reading neg rpm when spinning clockwise in low gear so I need to change the low spindle ratio to -0.117 instead of 0.117, but if I try to change it in the wizard I get the error in the attached pic and If I try to change it with parameter 65 in the plc ... as soon as I enter -0.117 and hit enter the parm 65 field changes itself to 0.0100 and will not except a neg number of any kind. I have cnc12 mill software as well as cnc12 lathe software both pro versions and my mill software excepted the neg number but the lathe software will not. What am I doing wrong?

The Wizard evidently does not allow you to have a low-range ratio that is slower than the medium-range ratio.

Do you really have a medium range with 100:1 reduction?

Does the rpm read normal + number before you start adding the figures in the MED LOW fields?
I have my medium field set to 0.6 to read the correct figure.
If your speed is still reading a negative number try removing the negative from the encoder counts field.

cncsnw wrote: ↑Sun Mar 31, 2024 12:51 am The Wizard evidently does not allow you to have a low-range ratio that is slower than the medium-range ratio.

Do you really have a medium range with 100:1 reduction?

Hi I have a medium speed range which in the manual is an M42 for the g code. Can you tell me why the g code doesn't recognise the M42 when i tell it to use medium speed ratio. It keeps defaulting to high speed ratio.

@PhilipTrueman, you should start your own thread instead of hijacking someone else's.

From the manual:

13.21 M41, M42, M43 - Select Spindle Gear Range (Macros)
M41, M42, and M43 have no default actions, and therefore custom macros must be defined for these M codes in order to make this feature work. If defined, these macros notify the PLC of which spindle gear range is selected according to the following table:
Macro M Fuction Action
M41 Select Low Gear Range M42 Select Medium-Low Gear Range M43 Select High Gear Range
Note that selecting a ”Medium-High” Gear Range is currently not supported by this schema, although that would not prevent a system integrator from defining another custom macro M function to do that.

cncsnw wrote: ↑Sun Mar 31, 2024 12:51 am The Wizard evidently does not allow you to have a low-range ratio that is slower than the medium-range ratio.

Do you really have a medium range with 100:1 reduction?

No I do not have med range at all . the numbers in that field were there when i installed the software and i have never changed them. But after your post i tried just clearing the med range field and the wizard will not allow it. so i tried changing it to a higher number than the low range field and when i do that i get no errors and the low range field excepts the negative number.... or so it seems untill i write settings and restart cnc12, at which point the system reverts both fields to 0.0100 ! (and if i try it from the plc it just reverts to 0.0100 as soon as i hit enter) This is crazy, lol . Is there a parm to disable the med range field all together? The wizard will not except 0.0 Thanks for your help!

PhilipTrueman wrote: ↑Sun Mar 31, 2024 5:24 am Does the rpm read normal + number before you start adding the figures in the MED LOW fields?
I have my medium field set to 0.6 to read the correct figure.
If your speed is still reading a negative number try removing the negative from the encoder counts field.

No it is still negative in low range(I don't have med range). If I make encoder counts a positive number it corrects low range but high range go's neg when spinning clockwise. Thanks for your suggestion.

cncsnw wrote: ↑Sun Mar 31, 2024 12:51 am The Wizard evidently does not allow you to have a low-range ratio that is slower than the medium-range ratio.

Do you really have a medium range with 100:1 reduction?

No i do not have med range, I changed the med range field to 1 (thanks for the advise) and the wizard allowed me to enter -.117 in the low range field and even wrote settings, but after restarting cnc12 the low range field has changed itself to .010. I have tried it more than once and also from the plc with no joy.

That appears to be a bug that has been introduced into CNC12. Centroid needs to fix it.

Parameters 65, 66 and 67 are allowed to be negative or positive; they just are not allowed to be zero.

cncsnw wrote: ↑Sun Mar 31, 2024 6:13 pm That appears to be a bug that has been introduced into CNC12. Centroid needs to fix it.

Parameters 65, 66 and 67 are allowed to be negative or positive; they just are not allowed to be zero.

I agree, the strange thing is that in cnc12 mill it works as expected which really makes me think its a mistake on my part but i cant seem to find one. LOL... And it wouldn't matter if I didn't need low gear to do some thread cutting (my spindle lacks torque below 1k rpm in high range) and as soon as cnc12 sees the negative spindle rpm it shuts down the program due to using css. I was able to make it work by removing the css and m3 command from the g-code & controlling the spindle manually but it produces a very ugly thread.